Protozoa/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby The video shows an animated scene of bacteria under a microscope. MOBY: Beep? The video shows a man, Tim, sitting at a table and looking through a microscope. A robot, Moby, is standing next to him. TIM: Well, these are the little suckers that made me sick last month. The video shows an animated scene of bacteria under a microscope. The video changes to show a letter from a fan. Tim reads the letter. TIM: Dear Tim and Moby, what exactly is a protozoan? From, Danforth. Protozoa are members of the protist kingdom. The video shows two rows and three columns of drawings with different species. The first row and first column has a graphic of a rat, and underneath the picture is the label, “Anamalia.” The second picture in the first row is of plants, and it is labeled “Plantae.” The third picture in the first row is of mushrooms, and it is labeled “Fungi.” The first picture in the second row is labeled “Protista.” The second picture in the second row is labeled “Eubacteria.” The third picture in the second row is labeled “Archaebacteria.” The video shows that all of the pictures are darkened except the picture labeled “Protista.” TIM: Protists are single- or multi-celled organisms that live in moist or wet surroundings. TIM: They can be plant-like, animal-like, or fungus-like. The video shows a black background, and the word, “protists,” appears in the upper right corner. On the left side is a mustard-colored rectangle with a cartoon-like picture of a tree. Underneath the rectangle is the word “plant-like.” The video shows two more graphics appearing to the right of the tree graphic. The center graphic looks like a blob with two dots inside that are lined up vertically. One dot is white and the other is purple. The blob-like structure is expanding and contracting. Underneath the graphic is the word, “animal-like.” The third graphic on the right looks like a multi-armed blob that is not moving. Underneath this graphic is the word, “fungus-like.” TIM: Protozoa are the animal-like protists. The video shows the two graphics on either side of the “animal-like” protist going dark. TIM: They’re all eukaryotic, meaning their cells have a nucleus. The video changes scenes to show an animation of protozoa under a microscope. MOBY: Beep? The video shows Moby beeping. TIM: Most species are found in the water, including oceans, lakes, rivers, and ponds. The video shows an animation of a pond with grass coming out of the water. TIM: But they also live in the soil and inside larger organisms, both living and dead. The video shows the animation of the pond getting smaller and moving to the upper left corner of the screen. In the upper right corner, another graphic appears of a cross-section of layers of soil. In the lower left corner, a graphic appears of a man, and in the right corner, a graphic appears of a dead bird. TIM: They may be tiny little things, but protozoa have a big effect on the Ecosystem. Some are parasites, meaning they live inside host organisms without providing any benefit, and in some cases, even harming the host. The video shows a graphic with a boy clutching his stomach. There is a large circle to the left of the boy. The circle is an animation of a microscopic view of three teardrop shaped objects with hairs coming out of the sides. All three have two dots toward the head of the teardrop. The background is dark orange, medium orange, and yellow like the colors of fire. In the upper left corner appears the word “parasitic.” TIM: Others live inside animals in symbiosis: they actually help the host! The video shows a graphic of a cow. A circle appears and zooms to the foreground. In the circle is an animation of a microscopic view of beneficial protozoa. These are shown as three shapes that look like green olives with hairs protruding from a flat edge. In the upper right corner of the screen appears the word “symbiosis.” TIM: Protozoa also control the earth’s population of bacteria, which many of them eat. The video shows Tim and Moby standing side-by-side in a room in front of a window. MOBY: Beep? TIM: Oh, they don’t really have digestive systems, at least the way we do. TIM: Protozoa have special spaces called vacuoles for digesting food and getting rid of excess water. The video shows a large protozoan. The graphic has the shape of the bottom of a shoe. Small hair-like protrusions line the entire outer surface of the protozoan. Inside the protozoan are two circles that have spikey protrusions all around them. There are also one larger and one smaller red disk-like figure and an oval inside the protozoan. The video shows another structure inside the protozoan that has an opening into which an oblong capsule-like structure enters. The word, “vacuoles,” appears in the top left corner of the screen. One of the circles with the spikey protrusions squeezes water out of the protozoan. TIM: Scientists have divided protozoa into four categories based on how they move. The video changes to show a grid with two columns and two rows. In the upper left box of the grid is a graphic of a blob-like protozoan with the label “ameboids.” In the upper right corner is a protozoan that looks like the silhouette of a mouse with a tail, and the label “flagellates” is underneath the graphic. In the lower left box is a graphic of a protozoan that has the shape of the bottom of a shoe with hair-like protrusions around the entire outer surface. Underneath this graphic is the label “ciliates.” The lower right box has a protozoan that looks almost circular and has a label underneath that reads “sporozoa.” The video changes to show an animation of an ameboid against a background of brownish-orange cells. The ameboid is blob-like and it constantly changes shape. There are two circles in the ameboid: one purple, and the other white. The word, “ameboids,” appears in the upper left corner of the screen. TIM: Ameboids use temporary extensions of their cytoplasm called pseudopods, meaning “false foot.” The word, “pseudopod,” appears on the screen and a line extends from the word to a protrusion of the ameboid. The words “false” and “foot” appear under the word, “pseudopod.” TIM: They also use the pseudopod to eat: it surrounds the food and engulfs it. Once the food’s trapped inside, a vacuole forms around it, and it’s digested. The video shows a capsule coming in from the left side of the screen and heading towards the ameboid. The ameboid changes shape to wrap around the capsule. A roughly circular shape appears around the capsule. AMEBOID: Burp! TIM: Many ameboids live inside exoskeletons made of calcium carbonate. The video shows the ameboid inside a capsule. Part of the ameboid is sticking out of the top of the capsule with three finger-like protrusions waving around. TIM: When they die, they often leave these skeletons behind, like shells. The video shows the ameboid disappearing from inside of the exoskeleton. TIM: Flagellates move using a flagellum, which is a little whip-like tail. The video shows the flagellate, which is shaped like a mouse, swimming on a blue background. The word “flagellates” is in the upper right corner, and the word “flagellum” appears with a line extending from the word “flagellum” to the “tail” of the flagellate. TIM: Because flagella only work in a liquid environment, most species of flagellates live in the water. The background changes to show the flagellate moving through water. The video changes to show a graphic of a large water droplet against a purple background. TIM: Some flagellates use their flagella to bring in food. The video shows a flagellate wiggling its flagellum to bring a capsule-like structure closer to itself. The capsule moves into the body of the flagellate. The flagellate then swims off the screen with the capsule. TIM: Ciliates move with cilia, which are tiny hairs. The video shows a large blue ciliate against a mustard yellow background. The ciliate has an outer grey layer and hair-like protrusions all around the outer surface. Inside the ciliate are four circles. In the upper left corner of the screen is the label, “ciliates.” The word, “cilia,” appears on the screen underneath the ciliate with three lines that extend from the word “cilia” to the hair-like protrusions on the ciliate. TIM: Like flagella, cilia work best in liquid. TIM: Ciliates are the most complex protozoans. The graphic changes to show the inside of the ciliate. There are small two blue circles, a larger and smaller red disk-like structure, and a tube-like structure that has an opening near the outer edge of the ciliate. Underneath the ciliate is the word, “Paramecium.” TIM: They have two nuclei — the micronucleus and the macronucleus. The video shows the word “micronucleus” appearing under the ciliate with a line extending to the smaller red disk-like structure inside the ciliate. Then, the word “macronucleus” appears with a line extending from it to the larger red disk-like structure. TIM: The macronucleus controls the day-to-day functions of the cell, and the micronucleus controls reproduction. The graphic of the macronucleus turns from red to yellow when Tim talks about it, and then it turns back to red. Then, the micronucleus turns yellow when Tim talks about it. TIM: Some ciliates live in symbiosis with cows and other grazing animals, helping them digest the grass they eat. The video shows a graphic of a cow. A circle appears, zooming out to the foreground. The circle has an animation of microscopic protozoa which look like green olives with hairs on the top that live inside the cow. The word “symbiosis” appears in the upper right corner of the screen. TIM: Sporozoa are parasitic, with no way of moving on their own for most of their lives. The video changes to show circular structures floating around against a background of dark reddish oval structures. The somewhat circular structures in the foreground have dark green outlines and dark green, circular center structures. The area in between the outline and the center portion of each structure is two shades of light green. In the upper right corner of the screen is the label “sporozoa.” In the lower left corner of the screen appears the label “parasitic.” TIM: Malaria, which kills millions of people every year, is caused by a sporozoan that’s spread through mosquito bites. The video changes and adds the label, “malaria,” appears in the lower left corner. The background is now like a cartoon version of fire. It has layers of red, orange, and yellow. In the foreground is a mosquito getting ready to plunge its stinger into some skin. A circle zooms out from the mosquito in front of the fire-like background. In the circle is a graphic of several sporozoa that look like little red beads. MOBY: Beep. TIM: Well, no, no — I don’t think that sporozoa are actually evil; that's just what they’ve evolved to do. The video changes to show Tim and Moby standing side-by-side in a room in front of a window. Tim is wearing a white t-shirt with pictures of the four different types of protozoa on the front. MOBY: Beep. TIM: I am not defending them! Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts